FTP
20/21
unsecured
SSH Secure Shell
22
SFTP (SSH FTP)
22
SMTP (email routing)
25
TACACS+ (cisco proprietary authentication protocol)
49
DNS
53
DHCP (network management protocol that automatically assigns IPs to devices)
67-68
HTTP
80
Kerberos (authentication protocol)
88
POP3 (email)
110
NetBIOS
125-139
IMAP (email management on server)
143, 993
SNMP (Simple Network Management Protocol)
161, 162
LDAP
389
HTTPS
443
TLS
LDAPS
636
TLS
FTPS
989/990
TLS
IMAPS
993
TLS
POP3S (email)
995
TLS
RADIUS
1812,1813
TLS
RDP (microsoft terminal server)
3389